Thats awesome, congrats! I have had my 3 sows on Oxbow Cavy Cuisine for a while now, so I guess if they ever had any calcium spots, they're gone now!
I've basically noticed that their skin/coat is so much better, and they always completely finish the bowl of pellets (1/8 cup per cavy), which they never used to do with Kaytee Rainbow Exact-ly junk food(
). They probably lick the dust out of the bowl too for all I know!